Fiber Optical Micro-detectors for Oxygen Sensing in Power Plants

Baker, Gregory L. ; Ghosh, Ruby N. ; III, D.J. Osborn ; Zhang, Po

Michigan State University

关键词: On-Line Measurement Systems;    Monitoring;    Oxygen;    Fiber Optics;    Molybdenum Chlorides;   

DOI  :  10.2172/876615
RP-ID  :  none
RP-ID  :  FC26-02NT41582
RP-ID  :  876615

美国|英语

来源: UNT Digital Library

【 摘 要 】

A reflection mode fiber optic oxygen sensor that can operate at high temperatures for power plant applications is being developed. The sensor is based on the {sup 3}O{sub 2} quenching of the red emission from hexanuclear molybdenum chloride clusters. Previously we described a particle-in-binder approach to immobilizing the potassium salt of a molybdenum cluster, K{sub 2}Mo{sub 6}Cl{sub 14}, at the tips of optical fibers. Compared to previous methods, the particle-in-binder approach affords fibers with greatly improved mechanical properties. We have extensively characterized two fiber sensors at high temperature. We obtain quenching ratios between pure nitrogen and 21% oxygen as high as 3.9 x at 70 C. For the first sensor at 60 C we obtained a {+-} 1% variation in the quenching ratio over 6 cycles of measurement, and monitored the device performance over 23 days. We were able to operate the second sensor continuously for 14 hours at 70 C, and the sensor quenching ratio was stable to 5% over that time period. These are promising results for a high temperature fiber optical oxygen sensor based on molybdenum chloride clusters.